Neighbor Selection For Handover in a Radio Access Network

Abstract

The following methods are disclosed: A method of initiating handover of a User Equipment, UE, in a cellular network comprising a plurality of enhanced Node Bs, eNBs, the method comprising: receiving at a source eNB, from the UE, a handover measurement report containing a Physical Cell Identifier, PCI, of a cell of a neighboring eNB; at the source eNB, performing a lookup of a Neighbor Relation Relation Table to identify a global cell identity and access mode associated with the PCI; and using the identified global cell identity and the access mode to determine an eNB identity for said neighboring eNB. A method of initiating handover of a User Equipment, UE, in a cellular net-work comprising a plurality of enhanced Node Bs, eNBs, the method comprising: receiving at a source eNB, from the UE, a handover measurement report containing a Physical Cell Identifier, PCI, of a cell of a neighboring eNB; at the source eNB, performing a lookup of a Neighbor Relation Table to identify a plurality of global cell identities associated with the PCI, the neighbor relation table also containing, for each such global cell identity, PCIs of neighboring cells; selecting the correct global cell identity from said plurality of global cell identities by comparing the PCIs of further neighboring eNBs cells reported by the UE with the neighboring PCIs of each of said plurality of global cell identities; and deriving from the selected correct global cell identity, an eNB identity of said neighboring eNB. A method of initiating handover of a subscriber from a cell of a source enhanced Node B, eNB, to a cell of a target enhanced Node B, eNB, via the X2 interface, the method comprising, at the source eNB, maintaining a Neighbor Relation Table (NRT) identifying the connectivity of the source eNB to cells of its neighboring eNBs, this information including for each eNB cell an indication that the eNB cell is an open, closed or hybrid eNB cell and, for each closed and hybrid eNB cell, a Closed Subscriber Group, CSG, identity; determining that a handover of the UE is required and using

Dependencies are inferred from the claim text.